In order to be effective, a tube clip must exert a substantial and relatively uniform pressure across the, whole of the width of the tube, it must also permit the clip to be drawn along the tube without unlatching the clip or without releasing the pressure; and it must also be relatively inexpensive to produce.
Inexpensive clips of various types are known in commerce, and typically they will comprise a pair of jaws, hinge means connecting the jaws for rotation, and a latch means for retaining,the jaws closed about an article. Clips of one type serve to close the wall of a thin film plastic bag. If it were attempted to close this type of clip about a tube, which will commonly have a wall thickness of some 10 to 20 times or more than that of a typical plastic bag, when the jaws initially contact the tube, the jaws will still be open at an appreciable angle. Should a force be applied in an effort to close the jaws, this will be expended by a substantial and unintended deformation of the jaws and the hinge structure to the point of breakage. Inexpensive clips of a second type include a spring means to bias the jaws shut. It is known to use a plastic spring means for this purpose, which may be integrally formed with the jaws of the clip. However, the pressures generated in such clips are relatively small, and unsuited for the present purposes. Moreover, these springs are pre-stressed under tension, and if it were attempted to pre-stress a simple plastic spring of the type which might find use in the manufacture of a simple and inexpensive clip, so as to provide a relatively high closure force suited for use in a tube clip, the spring tension would undoubtedly be reduced over a period of time due to plastic creep.
It is an object of this invention to provide a tube clip that is economic and effective for the desired purpose.
It is another object of this invention to provide a tube clip that may be moulded from plastic material, and that may be formed as a single, unitary piece.
It is yet another object of this invention to provide a tube clip of the foregoing nature that, while it utilizes a plastic spring means, will remain effective over a long period of time.